/**
 * Given a binary tree, return the inorder traversal of its nodes' values.
 * For example:
 * Given binary tree [1,null,2,3],
 * 1
 *  \
 *   2
 *  /
 * 3
 * return [1,3,2].
 */
/**
 * @author Ivan
 *
 */
package problem94_Binary_Tree_Inorder_Traversal;